Citation Analysis of Iranian Journal of Basic Medical Sciences in ISI Web of Knowledge, Scopus, and Google Scholar.

Objective(s): Citation tracking is an important method to analyze the scientific impact of journal articles and can be done through Scopus (SC), Google Scholar (GS), or ISI web of knowledge (WOS). In the current study, we analyzed the citations to 2011-2012 articles of Iranian Journal of Basic Medical Sciences (IJBMS) in these three resources. Material and Methods: The relevant data from SC, GS, and WOS official websites. Total number of citations, their overlap and unique citations of these three recourses were evaluated. Results: WOS and SC covered 100% and GS covered 97% of the IJBMS items. Totally, 37 articles were cited at least once in one of the studied resources. Total number of citations were 20, 30, and 59 in WOS, SC, and GS respectively. Forty citations of GS, 6 citation of SC, and 2 citations of WOS were unique. Conclusion: Every scientific resource has its own inaccuracies in providing citation analysis information. Citation analysis studies are better to be done each year to correct any inaccuracy as soon as possible. IJBMS has gained considerable scientific attention from wide range of high impact journals and through citation tracking method; this visibility can be traced more thoroughly.


Introduction
Scientific literature quality evaluation is an interesting subject for researchers to find out the prominent journals of their field. Assessing the scientific productivity of researchers, scholarly influence of the journals, and individual works is done using different bibloimetric techniques. Citation analysis is one of the major biliometrics methods for quality evaluation of the journals by analyzing the citations of journals which includes counting the citations, considering the citing items, and comparing citations distribution in different scientific indexing databases (1,2).
Citation analysis information used to be provided only by Web of Science (WOS) from ISI as the strongest scientific indexing database for years but since 2004, Scopus (SC) from Elsevier and Google Scholar (GS) from Google became two major resources for retrieving citation information in addition to WOS (3). Due to several differences among the three mentioned sources regarding their coverage, accessibility, updating half life, etc; all the mentioned sources should be considered while analyzing the citations of individual journals (4,5).
Iranian Journal of Basic Medical Sciences (IJBMS) is one of the leading Iranian journals in basic medical sciences which publish literature on anatomical sciences, biochemistry, genetics, immunology, microbiology, pathology, pharmacology, pharmaceutical sciences, and physiology.
IJBMS is indexed in ISI, SC, and GS and in 2011 received its first impact factor of 0.324 which is fairly high. In the current study we aimed to examine the citation analysis of IJBMS in these three scientific resources (WOS, SC, and GS), and to compare the discrepancies between their citation frequencies, and distribution.

Material and Methods
We considered all IJBMS articles published in 2011 and 2012. Citations to each article were extracted from all scientific databases and considered separately. Citations referred to all articles indexed in WOS, Scopus, and Google Scholar were extracted from their official website (6-8) using "cited by" feature for each article.   Coverage of databases, citation counts, and type of citing items were evaluated in each scientific database. The reasons of dissimilarity between IJBMS citation analyses of databases were evaluated in depth. Finally journals citing articles of IJBMS were analyzed according to their citation frequencies and 2011 Impact Factors (IF).
All information was retrieved on 10/2/2013 from the corresponding websites of the three mentioned resources (WOS, SC, GS).

Results
Overall 157 articles were published in IJBMS during 2011 and 2012. All of these articles could be located using WOS, and SC (100% database coverage). On the other hand GS had 97% coverage (5 articles could not be located by GS).
Totally, 37 articles were cited at least once in one of the studied databases (Table 1). Total number of citations was 20, 30, and 59 in WOS, SC, and GS respectively. Figure 1 shows the overlap and unique citations of each of the resources. Table 1 shows the details about citation analysis of IJBMS articles in the three WOS, GS, and SC. Table 2 shows the journals citing IJBMS articles in WOS and their Impact Factors (IF).

Discussion
For years, ISI form Web of Knowledge was the only scientific database for retrieving citation analysis information. Scopus and Google Scholar are two major additions to the citation analysis which can be considered as WOS rivals. Unlike WOS and SC, GS is a free extensive search engine. There is a considerable uncertainty regarding GS journal coverage, despite covering most of the journals and not-English articles (3). The major reason of the different citation counts in each scientific database was differences in journal coverage of each database. In our study the citation count of IJBMS resulted in different citation counts in three studied resources (GS: 59, SC: 30, and WOS: 20) and the highest citation belonged to GS. There were citations from journal articles not indexed in SC or ISI, but covered in GS. Different journal coverage of each database results in some unique citations for each scientific source too. In our citation analysis, 40 citations of GS, 6 citation of SC, and 2 citations of WOS were unique.
Type of the citing items also causes different citation analysis results. Books, meeting abstracts, conference papers, and doctoral and master's theses are usually considered only in GS citation counts (9). A study of IJBMS was cited by a proceeding paper which could be located by GS and SC but not by WOS (10).
Upgrading intervals of the databases is a factor that may cause different citation analysis results in specific time points. Scientific databases have different upgrading strategies and yield different citation counts at each time point. Some citations may be located in GS which are not included in ISI or SC yet. Almost 15% of GS citations were articles published in 2013 and were not included in SC, or ISI, at the time our data were extracted.
Inaccuracies of the databases in identifying the citations are another factor which resulted in different citation counts in the GS, WOS, and SC. Three articles of IJBMS showed discrepancies of citation counts of GS and WOS due to this fact. These citations could not be identified by WOS due to inaccurate indexing in WOS (11)(12)(13). Upon identification of these citations, we asked WOS to correct the inaccuracies which will be done in the upcoming months. A simple calculation shows that 2012 impact factor (IF) of IJBMS (which will be published in July 2013) actually increased by 0.026 (3/115; 115 is the number of IJBMS articles published in 2010 and 2011) through these corrections. This increase in IF shows the importance of citation analysis and we recommend citation tracking of IJBMS each year for detecting any WOS inaccuracies.
Language coverage is another difference between scientific databases. Most of the journals indexed in WOS and SC are English language journals, but GS covers many not-English language journal articles. In our study there were two citations from Russian and Spanish articles which were not indexed by WOS and SC, but GS counted them as citing items.
As shown in Table 2, IJBMS has been cited by variety of WOS indexed journals with impact factor as high as 4. This shows that IJBMS has got considerable visibility in scholarly world and has attracted the scientific researchers. Hopefully in the future this visibility would increase even more.

Conclusion
Every scientific resource has its own inaccuracies in providing citation analysis information. Citation analysis studies are better to be done each year to correct any inaccuracy as soon as possible. IJBMS has gained considerable scientific attention from wide range of high impact journals and through citation tracking method; this visibility can be traced more thoroughly.